Atomic write command support in a solid state drive

Abstract

A method of performing an atomic write command in a data storage device comprising a volatile memory and a plurality of non-volatile memory devices configured to store a plurality of physical pages. The method may comprise storing data in a plurality of logical pages (L-Pages), each associated with a logical address. A logical-to-physical address translation map may be maintained in the volatile memory, and may be configured to enable determination of a physical location, within one or more of the physical pages, of the data referenced by each logical address. The data specified by a received atomic write command may be stored one or more L-Pages. Updates to the entry or entries in the translation map associated with the L-Page(s) storing the data specified by the atomic write command may be deferred until all L-Pages storing data specified by the atomic write command have been written in a power-safe manner.

What is claimed is: 
     
       1. A method of performing an atomic write command in a data storage device comprising a volatile memory and a plurality of non-volatile memory devices that are configured to store a plurality of physical pages, the method comprising:
 storing data in a plurality of logical pages (L-Pages), each of the plurality of L-Pages being associated with a logical address; 
 maintaining a logical-to-physical address translation map in the volatile memory, the translation map being configured to enable determination of a physical location, within one or more of the physical pages, of the data referenced by each logical address; 
 receiving the atomic write command; 
 storing data specified by the atomic write command in at least one L-Page; 
 storing information tracking a range of L-Pages in which the writing of at least some L-Pages specified by the atomic write command have been completed, wherein the written L-pages can be written out of order; 
 in the event the atomic write command does not complete, at reconstruction: 
 using the stored tracking information to generate a copy command that copies a current version of L-Pages within the range that existed before the atomic write command; and 
 deferring an update to at least one entry in the translation map associated with the at least one L-Page storing the data specified by the atomic write command until all L-Pages storing data specified by the atomic write command have been written in a power-safe manner. 
 
     
     
       2. The method of  claim 1 , comprising:
 associating L-Pages of the atomic write command with a unique sequence number. 
 
     
     
       3. The method of  claim 2 , wherein storing information tracking a range of L-Pages comprises:
 updating a table that stores atomic write commands by their unique sequence numbers, wherein the table associates a minimum and a maximum value for each atomic write command; 
 finding in the table the unique sequence number of an L-page written by the atomic write command; 
 comparing a number associated with the L-page to the minimum and maximum value associated with the unique sequence number; 
 updating the minimum value with the number associated with the L-page if the number is less than the minimum value; and 
 updating the maximum value with the number associated with the L-page if the number is greater than the maximum value. 
 
     
     
       4. A data storage device controller, comprising:
 a processor, the processor being configured to perform an atomic write command in a data storage device comprising a volatile memory and a plurality of non-volatile memory devices that are configured to store a plurality of physical pages, by at least: 
 storing data in a plurality of logical pages (L-Pages), each of the plurality of L-Pages being associated with a logical address; 
 maintaining a logical-to-physical address translation map in the volatile memory, the translation map being configured to enable determination of a physical location, within one or more of the physical pages, of the data referenced by each logical address; 
 receiving the atomic write command; 
 storing data specified by the atomic write command in at least one L-Page; and 
 storing information tracking a range of L-Pages in which the writing of at least some L-Pages specified by the atomic write command have been completed, wherein the written L-pages can be written out of order; 
 in the event the atomic write command does not complete, at reconstruction: 
 using the stored tracking information to generate a copy command that copies a current version of L-Pages within the range that existed before the atomic write command; and 
 deferring an update to at least one entry in the translation map associated with the at least one L-Page storing the data specified by the atomic write command until all L-Pages storing data specified by the atomic write command have been written in a power-safe manner. 
 
     
     
       5. The data storage device controller of  claim 4 , wherein the processor is configured to:
 associate L-Pages of the atomic write command with a unique sequence number. 
 
     
     
       6. The data storage device controller of  claim 5 , wherein the storing information tracking a range of L-Pages comprises:
 updating a table that stores atomic write commands by their unique sequence numbers, wherein the table associates a minimum and a maximum value for each atomic write command; 
 finding in the table the unique sequence number of an L-page written by the atomic write command; 
 comparing a number associated with the L-page to the minimum and maximum value associated with the unique sequence number; 
 updating the minimum value with the number associated with the L-page if the number is less than the minimum value; and 
 updating the maximum value with the number associated with the L-page if the number is greater than the maximum value.